I'm agree with Jason to assay lipid per oxidation. Oxidative damages can be cause apoptosis or degeneration in neuronal cells. The mentioned changes can be detect by staining brain tissue with TUNEL assay (for apoptosis) or Tuloidine blue staining(for dark neurons) . you can read the attached paper...
Yes you can measure the antioxidants enzymes (superoxide dismutase; catalase; glutathione reductase, peroxidae and S transferase) by immunohistochemistry in brain paraffin sections.